Expandable vascular occlusion device with lead framing coil

ABSTRACT

An occlusion device for treating an aneurysm can have an inner embolic device with a proximal section and a distal section. The distal section has a first stiffness and the proximal section has a second stiffness. Further, the device has an expandable mesh capable of a collapsed position and an expanded position. The mesh can be disposed over, and attached to, a portion of the proximal section of the inner embolic device. The first stiffness is greater than the second stiffness and the inner embolic device has a preselected shape which assists in transforming the expandable mesh from the collapsed position to the expanded position.

FIELD OF THE INVENTION

The present invention generally relates to medical devices and methodswhich are used to occlude vessels within a patient, and moreparticularly, to occlusion devices which include an expandable mesh.

BACKGROUND

An aneurysm is an abnormal bulge or ballooning of the wall of a bloodvessel. Typically, an aneurysm develops in a weakened wall of anarterial blood vessel. The force of the blood pressure against theweakened wall causes the wall to abnormally bulge or balloon outwardly.One detrimental effect of an aneurysm is that the aneurysm may applyundesired pressure to tissue surrounding the blood vessel. This pressurecan be extremely problematic especially in the case of a cranialaneurysm where the aneurysm can apply pressure against sensitive braintissue. Additionally, there is also the possibility that the aneurysmmay rupture or burst leading to more serious medical complicationsincluding mortality.

When a patient is diagnosed with an unruptured aneurysm, the aneurysm istreated in an attempt to reduce or lessen the bulging and to prevent theaneurysm from rupturing. Unruptured aneurysms have traditionally beentreated by what is commonly known in the art as “clipping.” Clippingrequires an invasive surgical procedure wherein the surgeon makesincisions into the patient's body to access the blood vessel containingan aneurysm. Once the surgeon has accessed the aneurysm, a clip isplaced around the neck of the aneurysm to block the flow of blood intothe aneurysm and prevents the aneurysm from rupturing. While clippingmay be an acceptable treatment for some aneurysms, there is aconsiderable amount of risk involved with employing the clippingprocedure for treating certain types of cranial aneurysms because suchprocedures generally require open brain surgery and the location of theaneurysm can pose risks and may even prevent using this kind ofprocedure.

Intravascular catheter techniques have been used to treat cranialaneurysms, and are generally more desirable because such techniques donot require cranial or skull incisions, i.e., these techniques do notrequire open brain surgery. Typically, these techniques involve using acatheter to deliver an occlusion device (e.g., embolic coils) to apreselected location within the vasculature of a patient. For example,in the case of a cranial aneurysm, methods and procedures which are wellknown in the art are used for inserting and guiding the distal end of adelivery catheter into the vasculature of a patient to the site of thecranial aneurysm. A vascular occlusion device which is generallyattached to the end of a delivery member is then traversed through tothe delivery catheter until the occlusion is delivered into theaneurysm. The methods for delivering an occlusion device in a catheterare well known to those of skill in the art.

Once the occlusion device has been delivered to and deployed into theaneurysm, the blood within the aneurysm will generally clot in andaround the occlusion device to form a thrombus. The thrombus that formsseals off the aneurysm so that blood from the surrounding vessels nolonger flows into the aneurysm, this prevents further ballooning orrupture. The deployment procedure is repeated until the desired numberof occlusion devices are deployed within the aneurysm. Typically, it isdesired to deploy enough coils to obtain a packing density of about 20%or more, preferably about 35% and more if possible.

The most common vascular occlusion device is an embolic coil. Emboliccoils are typically constructed from a metal wire which may be woundinto a variety of shapes, including a helical shape. As explained above,a procedure may require using numerous embolic coils so that there is alarge enough surface area for blood to clot thereto. Sometimes theembolic coil may be situated in such a way within an aneurysm that thereare relatively considerable gaps between adjacent coils which can allowblood to freely flow into and within the aneurysm. The addition of extracoils into the aneurysm does not always solve this problem becausedeploying too many coils into the aneurysm may lead to an undesiredrupture.

Another technique is to use meshes, similar to stents, to fill theaneurysm. The benefit to these devices is that they can expand manytimes the diameter needed to deliver the mesh through the catheter. Thisallows for a smaller length of mesh, in comparison to embolic coils,needed to achieve packing densities above 35%. The smaller length isdictated by the fact that the mesh can expand and thus occupy more spacewithin the aneurysm even though it has a shorter length. By contrast, toachieve this same result, more (or longer lengths of) embolic coils areneeded since they retain their diameter to fill the same void. FIG. 22illustrates an example of a packing density comparison between a 1 mmouter diameter (OD) mesh, a 2 mm OD mesh and a 0.0150 inch (0.381 mm) ODembolic coil. In a 10 mm spherical aneurysm, an approximately 45%packing density is achieved with approximately a 7.5 cm length of the 2mm mesh, an approximately 45% packing density is achieved withapproximately 30 cm of 1 mm mesh and more than a 200 cm length of theembolic coil (at 0.015 in) is needed for an approximately 45% packingdensity.

This example highlights some of the challenges with mesh and emboliccoils. For the mesh, there may not be sufficient length of the mesh inthe aneurysm before density is reached. This leaves the mesh unsupportedand can lead to compaction. Compaction is as it sounds, the mesh iscompressed by blood flow into and past the aneurysm, and that decreasesthe portion of aneurysm treated by the mesh. Sometimes the portiontreated is decreased below the point of being effective and a secondprocedure is needed to refill the aneurysm to get a sufficient packingdensity. For the embolic coil, they are typically much shorter than 200cm and, as explained, multiple coils must be deployed into the aneurysmto reach an acceptable packing density, this increases the surgery timeas each embolic coil must be advanced through the catheter.

Therefore, there remains for a better occlusion device that provides agreater occupied volume to promote the clotting of blood and decreasesurgery time. The present invention presents such kinds of devices.Further, if multiple devices are used, the occlusion devices of thepresent invention can also effectively occupy the space between adjacentocclusion devices without increasing the risk of rupturing the aneurysm.

SUMMARY

Disclosed herein are various exemplary devices of the present inventionthat can address the above needs, which devices generally include aninner embolic device with a proximal section and a distal section, andmay also include an expandable mesh. In this manner, the devices of theinvention permit for one device to be used thereby minimizing surgicaltime, and achieving greater packing density using, for example, smallerlengths of devices and less devices.

In this context, the proximal section of the inner embolic device is theend closest to the physician and the distal section is the sectionfarthest away from the physician. The distal section can have a firststiffness and the proximal section can have a second stiffness. Theocclusion device can also include an expandable mesh capable of beingtransformed between a collapsed position and an expanded position. Theexpandable mesh can be disposed over, and attached to, a portion of theproximal section of the inner embolic device. The first stiffness of theinner embolic device can be greater than the second stiffness. Further,the inner embolic device can have a preselected shape which assists intransforming the expandable mesh from the collapsed position to theexpanded position.

Another example of the inventive occlusion devices includes anexpandable mesh covering substantially the entire proximal section ofthe inner embolic device. Also, the expandable mesh can have apreselected shape that it takes when transformed from the collapsedposition to the expanded position. That preselected shape of theexpandable mesh can assist in the transformation from the collapsedposition to the expanded position. Further, the inner embolic device canalso have a preselected shape at both its proximal and distal sections.

Further examples of the inventive occlusion devices include the innerembolic device having a transition zone between the first stiffness andsecond stiffness. The first stiffness can be up to approximately tentimes the second stiffness. Also, the occlusion devices can have aproximal section and a distal section that are of varying lengths. Forexample, a length of the distal section may be at least approximately 7%of the total length of the device. Here, the lengths of the proximalsection and the distal section can be equal, or one greater than theother. In another example, the length of the proximal section issubstantially longer than the distal section.

An example method of treating an aneurysm using an example of anocclusion device of the claimed invention can have the steps ofconfiguring the different stiffness of the inner embolic element so thatthe distal section is stiffer than the proximal section. The stifferdistal section can also be referred to as a framing coil. By this, asexplained in more detail below, the distal section “frames” the aneurysmso the proximal section that includes a mesh, can “fill in” the aneurysmto reach the proper packing density, as discussed above.

An occlusion device of the invention can be placed within a vessel of apatient and can be directed to the aneurysm. Once there, the distalsection/framing coil of the inner embolic element is deployed into theaneurysm, allowing it to take a predetermined shape (e.g., a shapedetermined in advance). This shape, as noted above, can “frame” theaneurysm. Once the distal section is in place, the remaining portion ofthe occlusion device is advanced. This deploys the expandable mesh, withthe proximal section of the inner embolic element, into the aneurysm.The mesh can then self-expand into its predetermined shape, filling theaneurysm to attain a packing density that is greater than that of theembolic coil alone.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and further aspects of this invention are further discussedwith reference to the following description in conjunction with theaccompanying drawings, in which like numerals indicate like structuralelements and features in various figures. The drawings are notnecessarily to scale, emphasis instead being placed upon illustratingprinciples of the invention. The figures depict one or moreimplementations of the inventive devices, by way of example only, not byway of limitation.

FIG. 1 is a side view of an exemplary vascular occlusion device of thepresent invention inside a catheter;

FIG. 2 is a view of an example of a vascular occlusion device of thepresent invention;

FIGS. 3-7 illustrate different examples of an inner embolic element(e.g. a framing coil once deployed, and a proximal section);

FIG. 8 illustrates a 3-D complex configuration of an inner embolicelement;

FIG. 9 illustrates an approximately 2-D simple helical configuration ofan inner embolic element;

FIG. 10 illustrates a side view of a self-expandable mesh;

FIG. 11 illustrates a partially cut-away side view of an inner embolicelement and the mesh, as assembled;

FIGS. 12a and 12b illustrate an example of a vascular occlusion devicewhere the coil can shape the mesh on deployment;

FIGS. 13a-13c illustrate an example of an embolic device beingrecaptured (i.e., pulled back into the catheter) after partialdeployment from the catheter;

FIG. 14 illustrates a mesh in an example of a non-uniform configuration;

FIG. 15 illustrates different examples of cross-sections for a mesh;

FIGS. 16a and 16b illustrate 3-D complex configurations of an embolicdevice, as deployed;

FIGS. 17a-17c illustrate the vascular occlusion device being deployedinto an aneurysm;

FIG. 18 is a flow chart of an exemplary method of the present invention;

FIGS. 19a and 19b illustrate a cross-sectional simplified comparisonbetween the prior art and an example of the present invention;

FIGS. 20a, 20d, and 20e illustrate multiple simple and complex shapesfor a vascular occlusion device;

FIGS. 20b and 20c illustrate an example of a deployed vascular occlusiondevice and a magnified section thereof;

FIG. 21 is a table illustrating examples of packing densities and lengthratios for the vascular occlusion device; and

FIG. 22 is a graph comparing the packing densities of prior art coilsand meshes.

DETAILED DESCRIPTION

FIG. 1 generally illustrates an example of a vascular occlusion device100 within a delivery catheter 10 and connected to a vascular occlusiondelivery system 20. The catheter is a typical catheter used forneurovascular procedures. The catheter size is selected in considerationof the size, shape, and directionality of the aneurysm or the bodylumens the catheter must pass through to get to the treatment site. Thecatheter 10 may have a total usable length anywhere from 80 centimetersto 165 centimeters and a distal length of anywhere between 5 centimetersto 42 centimeters. The catheter 10 may have an inner diameter (ID) ofanywhere between 0.010 and 0.030 inches. The outer diameter (OD) mayalso range in size and may narrow at either its proximal section ordistal section. The outer diameter may be 3 French or less. For thebelow examples, the proximal section of an inner embolic device is theend closet to the physician and the distal section is farthest away fromthe physician.

An occlusion device 100 typically exits the distal section 12 of thecatheter 10 to be deployed into an aneurysm 50. A proximal section 14 ofthe catheter 10 can house the delivery system 20. The delivery system 20is typically removeably connected to a proximal section 102 of theocclusion device 100 to deploy and/or retrieve the occlusion device 100out of the catheter 10 and into the aneurysm 50. Delivery systems 20 areknown to those of skill in the art and any can be used with any exampleof the present invention to deploy and/or retrieve coils, meshes, orother devices. Delivery systems 20 may include pusher members with anyof the known mechanisms to release the vascular occlusion device 100,which can include mechanical, electrical, hydraulic, or thermalmechanisms. In some examples, the vascular occlusion device 100 ispushed out of the catheter 10 and into the aneurysm 50, as opposed toplacing the catheter 10 and device 100 in the aneurysm 50 and removingthe catheter 10.

Turning now to an example of the occlusion device 100, as illustrated inFIG. 2, it has proximal 102 and distal 104 sections. The distal section104 can have an atraumatic tip 106, for example in the form of a weld,or solder bead and is thus designed to not cause any damage or injury totissues when advancing through a body orifice. The occlusion device 100can have two main parts, an inner embolic element 200 and aself-expanding mesh 300.

The inner embolic element 200 can act as a standard embolic coil. FIGS.3-7 illustrate different examples of the inner embolic element 200. Theinner embolic element 200 can have a proximal section 202 and a distalsection 204 and in some instances a transition zone 206. The innerembolic element 200 can act as a standard embolic coil, it may berelatively stiff or it may be relatively soft. The inner embolic element200 may be made with any biocompatible materials commonly used in theart such as nickel-titanium alloy, cobalt chromium alloys, Platinum,Nitinol, Stainless Steel, Tantalum, or other alloys; or any othersuitable biocompatible materials, or combination of these materials. Thestiffness of the inner embolic element 200 can be adjusted by, forexample, typical coil parameters of coil wire diameter, coil wounddiameter, coil pitch, and coil material. In the instance of a coil, thediameter of the coil is selected in consideration of the size and shapeof the aneurismal sac, which can be a variety of shapes and sizes. Theinner embolic element 200 may come in various random loop designs toconform to the aneurysm shape (discussed below). The number of loops, orturns, in a coil may also vary. Platinum coils may be between about0.008 inches and 0.025 inches in diameter. A coil may vary from about 1to 60 centimeters in length, with some as long as 100 centimeters. Theinner embolic element 200 can also be made of a radiopaque material suchas platinum or tungsten to provide radiopacity, which aids in thedelivery of the occlusion device 100.

A coil can vary along its length in softness and in stiffness. FIGS. 3-5illustrate different examples used to change the stiffness of the innerembolic element 200. This can be by opening the coil pitch (FIG. 3),increasing the coil diameter (FIG. 4), or using a smaller wire (FIG. 5).Additionally, a coil can be annealed in sections to soften the metal.FIGS. 6 and 7 illustrate another way of varying stiffness which is asingle inner embolic element 200 having a varying stiffness along itslength. In the figures, a transition zone 206 illustrates where thestiffness changes between the distal section 204 and the proximalsection 202, and the distal section 204 is stiffer than the proximalsection 202. Note other examples may have multiple transitions zoneswhere the stiffness may change numerous times when moving along thetotal length L.

In general proportions, the stiff distal section 204 of the innerembolic element 204 is typically greater than or equal to 5% of thetotal length L of the entire inner embolic element 200. In otherexamples, the stiff distal section 204 can be between approximately 20to 30 times the stiffness of the proximal section 202. Thus, thestiffness of the distal section 204 can be considered a first stiffnesswhile the stiffness of the proximal section 202 can be a secondstiffness. In FIG. 7, there can be a length of the distal section Ld anda length of the proximal section Lp that have different stiffness. Inexamples, the ratio of the length of the distal section Ld and thelength of the proximal section Lp are discussed below.

In another example of the inner embolic element 200, all or part of theelement 200 can be configured to form simple or complex predeterminedconfigurations or shapes once deployed from the catheter 10. FIGS. 8 and9 illustrate examples of different configurations. FIG. 8 illustrates acomplex, random three-dimensional shape, while FIG. 9 illustrates asimple two-dimensional helical shape. In another example, the distalsection of the inner embolic element 200 may take a configurationsuitable for framing the aneurysm. This “framing coil” portion is shapedto expand to the near periphery of the aneurysm. The portion of theinner embolic element between the two ends of the self-expanding mesh300 may take different configurations, e.g. one suitable foraccommodating the difference in length of the self-expanding mesh 300between the constrained and deployed state. The inner embolic elementmay consist of a single continuous coil or multiple sections of similaror different coils or other suitable devices joined together e.g. bywelding, soldering, crimping or other suitable method.

In one example, the proximal section 202, as identified by its length Lpin FIG. 7, and the distal section 204, as identified by its length Ld inFIG. 7, can take different configurations over the total length L, atleast based on their stiffness. In one example, when in the catheter 10,the portion of the inner embolic element 200 between the two ends of theself-expanding mesh can be under compression and this applies a tensileforce to axially or radially stretch out the self-expanding mesh 300, asin FIG. 11. Placing the mesh 300 in tension allows it to adopt itslongest length and smallest diameter (i.e. a collapsed state), thisprofile reduces frictional forces during delivery of the device. Thecompressed portion of the inner embolic element reverts to its naturalpre-formed state upon deployment of the device from the catheter 10.Designing the inner embolic element 200 to be in compression when in thecatheter can be by the use of different length wires to form the coils.A further design can be achieved during attachment of the mesh 300 toall or part of the proximal section of the coil. A slightly shorter mesh300 (in the constrained state in the catheter) than the length of thecoil between is attached to the coil so when the coil is straight insidethe catheter 10, the mesh 300 is in tension and in its collapsed state.

FIG. 10 illustrates a self-expanding mesh 300 which can include a tubeof mesh made of several materials such as deposited thin films. The selfexpanding mesh 300 can include multiple wires, for example from 4 to 96wires, and be made from multiple alloys such as a nickel-titanium alloy,cobalt chromium alloys, Platinum, Nitinol, Stainless Steel, Tantalum, orother alloys, or any other suitable biocompatible materials, orcombination of these materials. Also, these materials can be absorbableor non-absorbable by the patient over time. Additionally, although theself-expanding mesh 300 is illustrated as generally cylindricallyshaped, it is contemplated that the generally tubular element could alsobe in the form of different shapes, for example, an elongated generallycubical shape, discussed further below.

The apertures 304 in the mesh 300 create a substantially unitary framework or mesh in the wall 302. Thus, the apertures 304 may be of anysize, shape, or porosity, and may be uniformly or randomly spacedthroughout the wall 302 of the mesh 300. The apertures 304 provide thetubular element with flexibility and also assist in the transformationof the mesh 300 from the collapsed state to the expanded state, and viceversa.

The occlusion device 100, as noted above, can include the assembly ofthe inner embolic coil 200 and the mesh 300. In an example, to assemble,the inner embolic element 200 is inserted into an opening 306 located ateither end of the mesh 300 so that the mesh 300 covers at least aportion of the inner embolic element 200. As illustrated in FIG. 11, themesh 300 may cover substantially the entire proximal section 202, partof the proximal section 202, or the middle of the proximal section 202of inner embolic element 200, leaving at least the distal section 204uncovered. The mesh 300 can then be attached (not shown) to the innerembolic element 200 by friction fit, biocompatible adhesives, solder,welding, crimping or other approach suitable for use in the body. Inexamples, the mesh 300 can be connected to the inner embolic element 200in any number of places.

In one example, the mesh 300 covers a softer portion of the innerembolic element (coil) 200, for example, typically the proximal section202 of the coil 200. Thus, one end of the mesh 300 can be attached at ornear the transition zone 206. In examples, the distal section 204 of thecoil 200 is longer than the proximal section 202, based on thetransition zone 206. This is also true for the mesh 300, it can betypically shorter in length t than the proximal section length Lp of thecoil 200, and, in other examples, it can be shorter than 17%, 34%, or50% of the proximal section length Lp. In another example, the length tof the mesh 300 can be approximately equal to the entire proximalsection length Lp of the inner embolic element 200. The examples caninclude the length Lp slightly longer than the mesh 300 when the mesh300 is in the collapsed state. In one example, proximal section lengthLp is approximately 2-5% longer than the length l, or 1.02 l to 1.05l≈Lp. Further, the length of the mesh in its expanded position istypically less than the length l (i.e. when in the collapsed position).

As another example, take the deployed length, which is the entire lengthL and subtract out a minimal length of the distal section Ld_(min). ThisLd_(min) can be approximately 7% of total device length L. The length ofthe inner embolic device 200 under the mesh (the proximal portion insome examples) can be dependent on how much the mesh 300 foreshortenswhen the inner embolic element 200 also shortens. This leads to a rangeof length options. For this example, if the constrained mesh length l isno more than approximately 150% of unconstrained mesh length, then theration of the stiff distal section 204 of the inner embolic element 200is approximately 5% of the total length L of the entire inner embolicelement 200.

FIGS. 12a and 12b illustrate another example of assembling the mesh 300to the inner embolic element 200. Ends 308 of the self-expanding mesh300 ends can be secured to the proximal section 202 of a pre-shapedinner embolic element 200 while the inner embolic element 200 is in asubstantially straight configuration (e.g. under tension) as shown inFIG. 12a . Once unconstrained, after deployment from the catheter 10,the self-expanding mesh 300 expands and foreshortens, as shown in FIG.12b , creating internal space to allow for the pre-shaped inner embolicelement 200 to take its predetermined expanded form. This allows for theinner embolic element 200 to shape the self-expanding mesh 300. Theself-expanding mesh 300 can have a softness such that it allows for itsshape to be modified by the stiffness of the inner embolic coil 200. Inanother example, the inner embolic element (coil) 200 can have asoftness such that it allows for its shape to be modified by thestiffness of the self-expanding mesh 300 and conforms to the pre-shapedform of the self-expanding mesh 300. Thus, the proximal section 202 isshaped by the pre-determined shape of the mesh 300, and not necessarilypre-shaped itself.

In other examples, the pre-shaping of the inner embolic element 200 andthe expansion of the self-expanding mesh 300 are some the advantages tousing the occlusion device 100 during a procedure. FIGS. 13a-13cillustrate that an occlusion device 100 can be deployed and retrievedakin to either a standard coil or mesh. FIG. 13a illustrates anocclusion device 100 connected to its delivery system 20 inside of amicrocatheter 10. As the occlusion device 100 is pushed out of themicrocatheter 10 the device 100 takes its predetermined expanded shape.The inner embolic element 200 begins to foreshorten and the mesh 300begins to expand (FIG. 13b ). However, before full deployment andrelease, the occlusion device 100 can be recaptured into themicrocatheter 10, if desired (FIG. 13c ).

FIGS. 13a-13c also illustrate the proximal section (Lp) in compression.The pitch of the coils differs from that of the distal section (Ld) sothat the proximal section is in compression and wants to expand. Thisputs the mesh 300 in tension and it takes its collapsed state. This isillustrated in FIG. 13a . FIG. 13b illustrates the device 100 out of thecatheter 10, which allows the proximal section (Lp) to decompress andtake its preformed shape. At the same time the decompression removes thetension force from the mesh 300 to allow it to expand.

Turning back to the configuration of the mesh 300, FIG. 14 illustratesan example of a non-uniform configuration for the mesh 300 even whiletensioned by the coil 200. So, the mesh 300 can be straight/tube likewhen tensioned over the inner embolic element (coil) 200 in the catheter10. Other examples, the tensioned form of the mesh 300 can have anon-tube like shape. The mesh 300 can take any shape, with the caveatthat the shape must be able to be disposed in, and translate through,the catheter 10. The inner embolic element 200 as well can have apre-determined shape in the catheter 10 that is not straight, as long asit can be deployed. The shapes of the inner embolic element 200 and mesh300 can be similar, different, or complimentary, that is to say that themesh 300 and inner embolic element 200 may have different shapes, butthe shapes support or enhance the packing density. The shapes can be intwo or three dimensions.

In other examples, a mesh 300 can take even more complex configurationsalong with the underlying coil 200. FIG. 15 illustrates non-limitingexamples of cross-sections for a mesh 300. The examples include (1)round, (2) elliptical and/or oval, (3) a stadium and/or capsule, (4)half-circle and/or circular cap, and (5) triangular. These are2-dimensional descriptions of three dimensional shapes which can includespherical, spherical cap, hemispherical, ovoid, cylindrical, etc.

The examples of configurations of the inner embolic element, such as acoil, 200 and a mesh 300 result in the final shape of the occlusiondevice 100 once it is deployed from the catheter 10. FIGS. 16a and 16billustrate the complex 3D shape the occlusion device 100 can form oncefull deployed. FIGS. 17a-17c illustrate the occlusion device 100 beingdeployed into an aneurysm 50. The catheter 10 has been delivered througha body lumen 60 to the aneurysm 50. In FIG. 17a , just the distalportion 204 of the inner embolic element 200 has been deployed from thecatheter 10. The distal portion 204 can also be referred to as a framingcoil portion of the inner embolic element 200. The framing coil 204begins to take its predetermined shape and forms a structure thatoutlines and supports the walls of the aneurysm 50. After a length ofthe distal portion 204 is deployed, and in some examples, once thetransition zone 206 is passed, the proximal portion 202, with theself-expanding mesh 300, begins to be deployed from the catheter byusing the delivery member or other suitable technique.

FIG. 17b illustrates the majority of the occlusion device 100, both theinner embolic element, here shown as a coil 200 and a mesh 300, deployedout of the delivery catheter 10 and into the aneurysm 50. The device 100takes the shape of the aneurysm 50 similar, but unlike prior art emboliccoils, since it uses shorter coils and less coils. In addition, the mesh300 provides more surface area for blood clots to form and create athrombus. As the mesh 300 is deployed, it takes its predetermined shapeand/or the shape imposed upon it by the proximal section 202 of theinner embolic element 200. The mesh 300 begins to “fill in” thestructure formed by the framing coil, i.e. the distal, “unmeshed” end204. Finally, once the position of the occlusion device 100 issatisfactory, the device 100 is detached from the delivery system 20 andleft in the aneurysm 50, as illustrated in FIG. 17c . Using theinventive devices, surgeons may only need to use one device to achieve asatisfactory packing density without compaction, unlike prior artocclusion devices.

FIG. 18 illustrates an example of a method of treating an aneurysm withan example of the present invention. The method includes using any ofthe examples of the occlusion device 100 having the inner embolicelement, described here as a coil 200 and the expandable mesh 300, wherethe expandable mesh is disposed over a proximal part 202 of the innerembolic element 200. The distal part 204 of the inner embolic element200 can be a framing coil. The occlusion device 100 is placed within avessel or body lumen of a patient (step 400) and directed to theaneurysm (step 402). The distal portion/framing coil 204 is deployedinto the aneurysm (step 404) and takes on its predetermined shape (step406). Next, the expandable mesh 300 is deployed into the aneurysm, withthe proximal part 202 of the inner embolic element 200 (step 408). Theexpandable mesh 300 takes on its expanded shape (step 410). Anotherexample of the method can include a step of configuring or selectingdifferent stiffnesses for the inner embolic element so that the framingcoil/distal section is stiffer than the proximal section. For example,the stiffness can be determined in advance of the procedure using theexample configurations as disclosed above or methods known to those ofskill in the art. The surgeon can select the appropriately sized andstiffened occlusion device 100 for the needs of the patient at, orbefore, the time of the procedure.

FIGS. 19a and 19b provide a cross-section comparison of an interventionusing an occlusion device 100 of the present invention and conventionalcoiling procedures with conventional embolic coils. In conventionalprocedures (top of FIG. 19a ), a first coil, a framing coil 70, isdeployed into the aneurysm. The framing coil 70 is typically thestiffest, or firmest, and frames a “cage” in the aneurysm. The framingcoil 70 can be up to approximately 60 cm long. Additional coils, secondcoil 72, third coil 74, fourth coil 76, etc. are deployed into theaneurysm to continually fill the structure created by the framing coil70 until the aneurysm is filled to a density to achieve thrombosis. Thesecond, third, and fourth coils 72, 74, 76 are softer than the framingcoil 70 and can get progressively softer with each successive coil. Thesuccessive coils 72, 74, 76 are generally softer to minimize thepressure against the walls of the aneurysm to minimize the chance ofrupture. This conventional procedure typically requires 5-7 coils toachieve preferably greater than 25% packing density.

In contrast, FIG. 19b illustrates a mesh procedure using any of theexamples of the occlusion device 100 of the present invention. Here, thedistal section 204 of the inner embolic element 200 can act as a framingcoil. The proximal section 202 of the inner embolic element 200 alongwith the self-expanding mesh 300 is deployed into the aneurysm andreplaces the multiple coils used in the conventional procedure to fillthe structure created by the framing coil. The embolic device 100 canreach over a 40% packing density with a single deployed device. Thisminimizes both surgical time and complexity, as multiple coils do notneed to be individually deployed.

FIG. 20a illustrates examples of different shapes of deployed embolicdevices 100 as follows: (1) 2 mm diameter round mesh, sparse packing,complex shape; (2) 2 mm diameter round mesh, dense packing, complexshape; (3) 1 mm diameter round mesh, sparse packing, complex shape; (4)1 mm diameter round mesh, dense packing, complex shape, no coil; (5) 3mm wide, flat mesh, helical shape; (6) 3 mm wide, flat mesh, straightshape, coil in inner embolic element; (7) 2.4 mm major axis×0.8 mm minoraxis elliptical mesh, helical shape; and (8) 2 mm diameter round meshformed with intermittent beads.

FIGS. 20b and 20c illustrate another example of a deployed occlusiondevice 100. FIG. 20c is a magnified section of the deployed device ofFIG. 20b . Identified is the mesh portion over the inner embolic element200, (i.e. the proximal section Lp with the mesh 300) and the framingportion of the inner embolic element 200, (i.e. the distal section Ldwith embolic element 200). Here both are fully deployed and in FIG. 20cthe mesh 300 is in its expanded state. FIGS. 20d and 20e are two otherexamples of the deployed vascular occlusion device of the invention.

FIG. 21 illustrates a number of example ratios of distal section lengths(Ld) vs. total device lengths (L). The calculations are for aneurysmsranging from 4 mm to 34 mm in diameter. Assumptions for the calculationsare that the distal section 204 is to “frame” the aneurysm 50 and theproximal section 202 with the mesh 300 over it is to “pack” theaneurysm. FIG. 21 illustrates ratios for a length of the distal sectionLd and a length of the deployed self-expanding mesh over the proximalsection l (see, FIGS. 7 and 10). The examples are considered idealizedbecause of a number of assumptions, one is that the coil forms a‘spherical shell’ of uniform thickness equal to the coil diameter (0.635mm=0.025″ and 0.2032 mm=0.008″), the outer diameter of the shell isequal to the aneurysm diameter and the hollow sphere the shell forms ispacked with mesh to an equal packing density as the coil in the shell.In other examples, the mesh in the hollow sphere is packed at twice and4 times the packing density as the coil in the shell. In these examples,packing density calculations assume the mesh maintains its unconstraineddiameter during packing. Because meshes are compressible, unlike coils,it is possible to pack meshes to much higher packing densities thancoils. These dimensions and calculations are intended to be illustrativeand are in no way intended to limit the scope of the claimed invention.

Exemplary embodiments may have ratios between the Ld and the devicelength L total varying between 7% to 97.3%. Other ratio ranges caninclude between approximately 10% to approximately 23%, approximately30% to approximately 45%, approximately 52% to approximately 69%,approximately 71% to approximately 85% and approximately 90% toapproximately 97%.

In addition to the examples disclosed above, in which the framing coilis deployed into an aneurysm first as the distal section and the meshfollows along with the proximal section of the inner embolic element,the deployment order can be reversed. Thus, it is possible to deploy theproximal section of the inner embolic element carrying the mesh and thendeploy the distal section, i.e. the framing coil. In an example of thereversed configuration, any or all of the other parameters discussedabove can be utilized. Alternately, variations in the stiffness andlengths between the framing end and the braided end can be changed basedon the nature of the deployment.

The descriptions contained herein are examples of embodiments of theinvention and are not intended in any way to limit the scope of theinvention. As described herein, the invention contemplates manyvariations and modifications of the inventive vascular occlusion device,with framing coil, including numerous inner embolic elements, coilconfigurations, numerous stiffness properties for the inner embolicelement, numerous mesh configurations, numerous materials for the innerembolic element and mesh, and methods for delivering the same. Also,there are many possible variations in the materials and configurationsof the release mechanism. These modifications would be apparent to thosehaving ordinary skill in the art to which this invention relates and areintended to be within the scope of the claims which follow.

What is claimed is:
 1. An occlusion device comprising: an inner embolicelement comprising a proximal section and a distal section, wherein thedistal section has a first stiffness and the proximal section has asecond stiffness that differs from the first stiffness; and anexpandable mesh capable of being transformed between a collapsedposition and an expanded position, wherein the expandable mesh isdisposed over a portion of the proximal section of the inner embolicelement, and wherein the occlusion device is permanently deployed intoan aneurysm.
 2. The occlusion device of claim 1 wherein the innerembolic element comprises a coil having a predetermined preselectedshape that assists in transforming the expandable mesh from thecollapsed position to the expanded position.
 3. The occlusion device ofclaim 1 wherein the expandable mesh covers substantially the proximalsection of the inner embolic element.
 4. The occlusion device of claim 1wherein the expandable mesh comprises a predetermined shape.
 5. Theocclusion device of claim 4 wherein the expandable mesh takes on thepredeterimed shape once in the expanded position.
 6. The occlusiondevice of claim 1 wherein the inner embolic element further comprises atransition zone where the first stiffness changes to the secondstiffness.
 7. The occlusion device of claim 1 wherein the firststiffness is one of greater than or less than the second stiffness. 8.The occlusion device of claim 1 wherein the first stiffness is at leastapproximately ten times the second stiffness.
 9. The occlusion device ofclaim 1 wherein the first stiffness is up to approximately twenty timesthe second stiffness.
 10. The occlusion device of claim 1 wherein thefirst stiffness is up to approximately thirty times the secondstiffness.
 11. The occlusion device of claim 1 wherein the proximalsection of the inner embolic element is in tension and the expandablemesh is in compression when the expandable mesh is in the collapsedposition.
 12. The occlusion device of claim 1 wherein the distal sectioncomprises a distal length, the proximal section comprises a proximallength, and the distal length is at least 7% of a total length of theinner embolic element.
 13. The occlusion device of claim 12, wherein theexpandable mesh has a mesh length in the collapsed position, and whereinthe proximal length of the proximal section is approximately 2%-5%longer than the collapsed mesh length.
 14. The occlusion device of claim1, wherein the inner embolic element comprises a coil having apredetermined shape.